ART: Add verifier support for invoke-polymorphic.

Change-Id: I1e1860cad80db46320c3ef5a9eaceb7529ea68d7
Bug: 30550796,33099829,33191712
Test: make test-art-host
diff --git a/runtime/art_method.h b/runtime/art_method.h
index 0e1d7e7..daef35d 100644
--- a/runtime/art_method.h
+++ b/runtime/art_method.h
@@ -245,6 +245,10 @@
     return (GetAccessFlags() & kAccSynthetic) != 0;
   }
 
+  bool IsVarargs() {
+    return (GetAccessFlags() & kAccVarargs) != 0;
+  }
+
   template<ReadBarrierOption kReadBarrierOption = kWithReadBarrier>
   bool IsProxyMethod() REQUIRES_SHARED(Locks::mutator_lock_);